To build the tester, the mechanical components need to be made from the plans below. The actual assembly is very straight forward and intuitive, but you can use the gallery for reference photos.

One note is the upper loading platen and the platen spacer have 4-40 tapped holes to join the two parts together with a .25” piece of 4-40 threaded rod coated in loctite or some epoxy. You can get this threaded rod by just cutting a section of a 4-40 screw off.

The bottom loading platen is a salvaged glass hemisphere. This gives the tester a self leveling ability. However no commercial source of the glass is known so you will need to design the bottom platen part around a hemisphere you find or make it flat and lose the self leveling.

2 feet 3030 style 80/20 extrusion. Making the pillars 12 inches seems a little short, so rather than making 12 inch pillars with feet to get the height needed, you could buy 4' of stock and make 15 inch pillars for the tester. This costs a lot more so the funky feet fix was chosen.